The speed of it is not stable. It can start at 50mb/s and then drop to 4mb/s after 12 seconds. Also, recently it has shown me a problem where the recording does not complete (I have noticed this in movies), resulting in the file not being copied correctly.

Not fast at all, however small and user-friendly. Heats up excessively. Regretted the purchase, which was very cheap

It broke in less than 4 months. The speeds were satisfactory, but nothing special. The dual plug was convenient for transferring to and from the mobile as well as for watching movies on it.
Its construction is unacceptable and in less than 4 months the plastics had come off.

I have had it in my possession for 3 months now (and the 32gb one for over a year).

Small in size. Plastic construction, nothing special but especially the 128gb one I have with me for work purposes and it has been through a lot without any issues. Of course, it requires attention. Attention is also needed when using the "button" that pushes either the usb male or the micro usb male connector. By saying attention, I don't mean to overdo it, but also not with force or abruptly (after all, it is not necessary). It is fast and so far I have had no connectivity problems either on a PC or on MLS tablet, Lenovo A7000, Huawei P10 Lite, Xiaomi Redmi Note 4X. I imagine it won't have any issues with any OTG Ready device. In the middle, as shown in the photos, it has a metal loop to attach a string.

In the link below is the compatibility chart of Sandisk for all the usb flash drives of the Ultra Dual series: https://kb.sandisk.com/app/detect

From speed, nothing special. The problem is that it overheats excessively. I transferred an 11 GB file and as soon as the transfer finished, it was burning!

It is very convenient to use with Android mobile phones and tablets, while it can also be used as a regular stick on televisions and computers!
It requires a little more attention in handling compared to regular sticks.
Satisfied with its performance, especially on devices with USB 3.

It sticks horribly (the speed drops down to 1mb/sec!!!) when transferring large files, due to the fact that it overheats.

The mechanism for switching from usb-a to usb-b does not inspire confidence.
At least it does its job as an otg.

I'm giving it 3 stars just so the overall rating doesn't drop.

Mediocre quality construction and speed, but for a total of 33 euros that I paid including shipping and cash on delivery, it is worth it and more for 64GB and the Sandisk warranty. I highly recommend it to those who do not expect extreme durability or speed. Otherwise, it is extremely useful, especially with the SanDisk application for Android and iOS.

In 2 months the plastic broke and it doesn't come out of it. I have to remove the plastic or go and change it.

I bought these USB sticks because of the USB for mobile phones (attention, for android only FAT OXI NTFS). The format is exFAT but still doesn't read large files. I preferred them over a 128GB one. Good warranty, small and practical the little iron piece to hold it with a small ring, for example on keys.
-1 star: The capacity is not 64GB but 59GB in total.
-1 star: Writing speed (with USB3) didn't go over 18MB/s and for reading over 50MB/s.

It has very good data transfer speeds of 130mb/s Read and 34-42mb/s Write. Its construction is convenient, it is small and you can add it to your keychain without needing additional wires, ropes, etc. As for the connection to a mobile device with OTG, I have to say that Android only supports the FAT32 file system, so it needs to be formatted in this way for the mobile device to read it (although some Samsung devices support NTFS). There are certain programs that allow Android to read NTFS and other formats, such as Paragon UFSD root mounter (requires ROOT) or exFAT/NTFS for Total Commander (needs to be purchased / does NOT require ROOT)

It has solved my hands! Instead of connecting my tablet / phone to my computer every time to transfer files, I simply use this specific flash drive! Personally, I love it because I don't have to struggle with cables every time I need to transfer large files, as the write and transfer speeds are very good.

Very good for its price!

It is fast, has a decent capacity, and easy to handle. You download the app from the playstore and that's it! It is very beautiful and small. Just sometimes it overheats, but only if you use it heavily.

I definitely recommend it to you!